JSON Syntax Error when Logging into GUI

When logging into the GUI via my duckdns URL, I get the following:

Uncaught SyntaxError: Unexpected token N in JSON at position 11784
    at JSON.parse (<anonymous>)
    at a._handleMessage (core-8f7092d0539f93e721211e2ee881a5f7.js:1)
a._handleMessage @ core-8f7092d0539f93e721211e2ee881a5f7.js:1

Does anyone know what this is about? I’ve had problems logging into the GUI since late last night…This is the furthest I’ve gotten and I can’t seem to find anything about it on the forum or on google. Please let me know what information you need because I honestly have no idea where this comes from.

I figured it out - min_max sensor wasn’t working. Is there any way to do the following code in a template?

if(bedroom_real_feel != null) {
input = bedroom_real_feel;
} else {
“don’t use this sensor”
}